Switching of Magnetization in Quantum Antiferromagnets with Time-Dependent Control Fields

Abstract

Ultrafast manipulation of magnetic states is one of the necessities in modern data storage technology. Quantum antiferromagnets are promising candidates in this respect. The orientation of the order parameter, the sublattice magnetization, can be used to encode "0" and "1" of a bit. Then, the switching of magnetization and the full control of its reorientation are crucial for writing data. We show that the magnetization can be switched efficiently by an external short THz pulses with relatively low amplitude. The coupling to the spin degrees can be direct via the magnetic field or indirect via the electric field inducing spin-polarized charge currents. Our description is based on time-dependent Schwinger boson mean-field theory which includes the intrinsic dephasing mechanisms beyond a macrospin description. The findings help to introduce the use of antiferromagnets in data storage technology.